Process for producing crystalline propylene polymer

ABSTRACT

Crystalline propylene polymer is produced with a very high efficiency and with few formation of amorphous polymer, from propylene or propylene together with Alpha -olefin by contacting propylene or propylene together with Alpha -olefin with a catalyst comprising (1) a size-controlled and heat-treated TiCl3.0.33AlCl3 and (2) a dialkylaluminum monohalide or a combination of an alkylaluminum dihalide and Si(OC2H5)4, said size-controlled and heat-treated Ti-Cl3.0.33AlCl3 being prepared by reacting TiCl4 with Al powders in a mol ratio of TiCl4 to Al greater than 3:1, removing unreacted TiCl4, size-controlling the resulting powders of TiCl3.0.33AlCl3 by ball-milling in a ballmill containing the same or substantially the same size of steel or stainless steel balls having a diameter of 25 - 50 mm, at room temperature, to give size-controlled powders consisting of 50 % or more of the particles of 325 meshes on and less than 50 % of the particles of 325 meshes pass, and heat-treating the sizecontrolled powders at specified conditions of temperature, pressure and time.

United States Patent 1 Shirai et al.

[ July 29, 1975 i 1 PROCESS FOR PRODUCING CRYSTALLINE PROPYLENE POLYMER \[75] Inventors: Isoo Shirai; Takeshi Suzuki; Koichi Tonooka, all of lchiharashi, Japan Related US. Application Data [63] Continuation-impart of Ser. No. 160,281, July 7,

1971, abandoned.

[30] Foreign Application Priority Data FOREIGN PATENTS OR APPLICATIONS 826,908 l/l960 United Kingdom OTHER PUBLICATIONS Stauffer, Product Data Sheet, Stauffer Chemical Co.,

Specialty Chemical Division, Westport Ct. (Jan.

Primary Examiner-Edward .1. Smith Attorney, Agent, or Firm-Fred Philpitt [57] ABSTRACT Crystalline propylene polymer is produced with a very high efficiency and with few formation of amorphous polymer, from propylene or propylene together with a-olefin by contacting propylene or propylene together with a-olefin with a catalyst comprising (1) a size-controlled and heat-treated TiCl .0.33AlCl and (2) a dialkylaluminum monohalide or a combination of an alkylaluminum dihalide and Si(OC l-l said size-controlled and heat-treated TiC13.0.33A1C1 being prepared by reacting TiCl with A1 powders in a mo] ratio of TiCl, to Al greater than 3:1, removing unreacted TiCl size-controlling the resulting powders of TiCl .0.33AlCl by ball-milling in a ball-mill containing the same or substantially the same size of steel or stainless steel balls having a diameter of 25 50 mm, at room temperature, to give size-controlled powders consisting of 50 or more of the particles of 325 meshes on and less than 50 of the particles of 325 meshes pass, and heat-treating the size-controlled powders at specified conditions of temperature, pressure and time.

5 Claims, 1 Drawing Figure PROCESS FOR PRODUCING CRYSTALLINE PROPYLENE POLYMER This application is a continuation-in-part of Ser. No. 160,281, filed July 7, 1971 and now abandoned.

DESCRIPTION OF THE INVENTION This invention relates to a process for producing a crystalline propylene polymer, and more particularly to a process for producing a highly crystalline propylene polymer by a novel catalyst (the term polymer referred to herein means both homopolymer and copolyrner of propylene).

It is well known to obtain a crystalline polyolefin by contacting olefins with a catalyst system consisting of organometallic compounds of metals of the Groups 1 to 111 of the periodic table, and halides of transition metals of the Groups 1V to VI of the periodic table in the presence or absence of an inert solvent. It is also well known that an organo-aluminum compound as an organometallic compound and titanium trichloride or titanium tetrachloride as a halide of transition metal can be advantageously used in an industrial scale to obtain crystalline polyolefins.

In that case, a combination of titanium trichloride catalyst and trialkylaluminum, for example, trienthylaluminum, has a very high polymerization activity in the polymerization of a-olefin, particularly propylene, but a ratio of formation of amorphous polymer is also high. On the other hand, it is well known that the catalyst system, wherein dialkylaluminum monohalide, for example, diethylaluminum monochloride, is used in place of trialkylaluminum, is inferior in the polymerization activity to the catalyst system where trialkylaluminum is used, but the ratio of formation of amorphous polymer is considerably lower. Therefore, it can be said that a catalyst system of titanium trichloride catalyst-diethylaluminum monochloride is advantageous in a practical usage.

However, since the increase in the ratio of formation of amorphous polymer increases the production cost, it is very important to lower the ratio of formation of amorphous polymer in commercial operation, and therefore even only 1 reduction of the amorphous polymer based upon produced total polymer including the amorphous polymer, is regarded as a considerable improvement.

The improvement in the ratio of crystalline polymer to amorphous polymer formed is generally carried out by adding the third component to a combination catalyst of an organo-metallic compound and a transition metal compound (which is usually called Ziegler- Natta Catalyst). The catalyst of the present invention is different from the above-mentioned catalyst systems in the use of highly activated titanium trichloride catalyst itself, that is, a highly activated solid solution containing a transition metal compound.

1n addition to said method based on the addition of the third catalyst component, the following methods have been proposed to lower the ratio of formation of the amorphous polymer. For example, an increase in the rate of polymerization and decrease in the ratio of formation of amorphous polymer can be effected by heating a catalyst component mixture, which consists of at least one of vanadium trihalide and titanium trihalide, and an organoaluminum sesquihalide at a temperature of 80 180C in the absence of polymerizable olefin prior to the polymerization (Japanese Patent Publication No. 16055/67).

Further, the decrease in the ratio of formation of the amorphous polymer can be carried out by polymerizing propylene or a mixture of propylene and a small amount of ethylene in the presence of as a catalyst system, a combination of an organoaluminum compound and titanium trichloride heat-treated after addition of a halogen compound of groups IV and V of the periodic table (exclusive of titanium trichloride) (Japanese Patent Publication No. 11150/70). However, according to any of these processes, the effectiveness of reducing the formation ratio of amorphous polymer to crystalline polymer is insufficient as compared to the process of the present invention.

An object of the present invention is to produce a crystalline propylene polymer in high yield (the reduction in the proportion of amorphous polymer) without any influence upon the rate of polymerization, molecular weight of polymer and bulk density of solid polymer.

This object can be attained by using a catalyst consisting of a TiCl .0.33AlCl catalyst prepared from the reduction of TiCl with Al powder, subjected to sizecontrolling specified hereinafter described and heattreated under the atmospheric or reduced pressure but under the conditions as described below without any addition of a treating agent in advance.

That is to say, said object can be attained by using a catalyst comprising (1) a size-controlled and heattreated TiCl .0.33AlCl and (2) a dialkylaluminum monohalide having a general formula of AIR X (wherein R is a hydrocarbon radical and X is a halogen atom) or a combination of an alkylaluminum dihalide having a general formula of AlR'X (wherein R is a hydrocarbon radical and X is a halogen atom) and Si- (OC H said size-controlled and heat-treated TiCl .0.33AlCl being prepared by reacting TiCL, with Al powders in a mo] ratio of TiCL, to Al greater than 3:1, removing unreacted TiCl size-controlling the resulting powders of TiC1 .0.33AlC1 by ball-milling in a revolving or vibrating ball-mill containing the same or substantially the same size of steel or stainless steel balls having a diameter of 25 50 mm, at room temperature, to give size-controlled powders consisting of 50 or more of the particles of 325 meshes on and less than 50 of the particles of 325 meshes pass and heattreating the size-controlled powders at a temperature of to 250C under a pressure of 0.01 to 760 mm Hg for l to 300 minutes and further under specified relationships (I) between temperature, pressure and time as described below.

Another advantage of the present invention is that a crystalline polymer can be obtained in high yield without using such a complicated method as other well known methods, for example, in which other treating agents are used for titanium trichloride. Further, when the TiC1 .0.33AlCl is used together AlR X, a combination of these two components with a well known third component may be utilized to make the effectiveness of addition of the third component exhibit.

The above-mentioned preparation of the sizecontrolled and treated TiCl .0.33AlCl will be more particularly explained hereunder.

Three mols or more, preferably five mols or more of TiCl, is reacted with one mol of Al powder in the presence of 0.02 0.4 mol of TiCl .0.33AlCl with stirring under atmospheric pressure at a temperature of 60C or higher but lower than the boiling point of TiCl and after completion of the reaction, an excessive amount of TiCl, is removed by distillation at a temperature lower than 160C to give violet powders of TiCl .O.- 33A1Cl whose sizes are controlled by milling in a ball mill to give a violet product having a composition of TiCl .0.32-0.33AlCl and a content of 0.0l0.1 by weight of TiCl As for the above-mentioned ball-mill treatment, an embodiment (A) will be illustrated hereunder. I

(A) 800 g of the above-mentioned violet powders of TiCl .0.33AlCl was milled in a 800 cc air-tight vibrating ball mill with a vibration number of 1,000 v.p.m. and an amplitude of 6 mm, at room temperature for 60 hours to yield size-controlled TiCl .0.33AlCl having a particle size distribution of 12.4 of particles of 80 mesh on, 15.8 of particles of 80 mesh pass and 200 mesh on, 26.9 of the particles of 200 mesh pass and 325 mesh on and 44.9 of the particles of 325 mesh pass. Powdery form of TiCl .0.33AlCl before sizecontrolling contained a large amount of components of very fine powders and had less than 10 of those of 325 mesh on and greater than 90 of those of 325 mesh pass.

Thus sized-controlled titanium trichloride catalyst can be used, as it is, together with an organoaluminum compound, for polymerizing propylene.

As for the effectiveness of the size-control, when the size-controlled catalyst is used for polymerization of e.g. propylene, it gives polypropylene products having a large bulk density. Namely, (1) into a 1.5 1 stainless steel autoclave equipped with an electromagnetic stirrer and flushed with nitrogen gas after evacuation of air by connecting to a vacuum pump, there was introduced 1.0 l purified hexane and then 0.3 g of the abovementioned TiCl .0.33AlCl which had not been sizecontrolled and 0.5 g of AlEt Cl were added thereto. After addition of 40 ml of hydrogen, temperature was elevated to 70C and then polymerization of propylene was carried out under a propylene pressure of 10 Kg/cm (gauge) for one hour. After polymerization, 100 ml of methanol was added and treated at 70C for 30 minutes. After the treatment, resultant polymer slurry was filtered off and white polypropylene powder having a bulk density of 0.30 was obtained by vacuum drying of the polymer. (2) Whereas, when polymerization was carried out in the same manner as in the above-mentioned polymerization test (1) except that the size-controlled TiCl .0.33AlCl obtained in the above-mentioned size-control test (A) was used as catalyst, the bulk density of the resultant polypropylene was 0.44 which was a much higher value compared to the bulk density of the polypropylene of (1). On the other hand, the proportions of atactic polypropylene to total polypropylene were 5.5 in case of l) and 5.1 in case of (2), respectively (which shows that there is no much difference).

The titanium component of the catalyst of the present invention has a composition of TiCl .(0.32-0.3- 3)AlCl as mentioned above, and the content of free TiCl in the catalyst is only a slightest amount of 0.01 to 0.1 by weight. This content of TiCl does not vary even by the heat treatment of the catalyst carried out under the atmospheric or reduced pressure.

According to the X ray diffraction method, the violet TiCl .0.33AlCl has a y-type of crystalline structure.

When the above-mentioned size-control is carried out in a ball-mill by using balls having a diameter less than 25 mm, size-controlling effect is not good, and it is difficult to bring the particle size distribution of TiCl .0.33AlCl to 50 or more of particles of 325 mesh on. When balls having a diameter greater than 50 mm are used, size-control requires a long period of time e.g. several hundred hours and hence such is not economical.

Important factors for the conditions of treating the size-controlled TiCl 0.033AlCl are a heating temperature, whether the atmospheric pressure is used or not or how much a degree of pressure reduction is, and a treating time, and a combination of these three factors becomes a further important factor. That is, it is difficult to increase the yield of crystalline polymer when the polymerization of propylene, or propylene and other a-olefin is carried out in the presence of the sizecontrolled TiCl .0.33AlCl treated under such a condition that these three factors are beyond the suitable ranges.

Among these three factors, particularly the heating temperature has an unsuitable range, irrespective of other two factors. That is to say, no effect can be attained at all or almost at all, if the heating temperature is less than C, almost independently from the degree of pressure reduction and the treating time. Furthermore, no effect or adversely a bad effect is attained likewise when the heating temperature exceeds 250C. Therefore, the preferable heating temperature is in a range of to 220C.

As an industrially practicable range for the atmospheric pressure or the degree of pressure reduction, a range of 0.01 to 760 mm Hg can be selected. As a practical range for the treating time, a range of l to 300 minutes can be selected.

However, even if these three factors are within the said defined ranges, a good result is not always obtained by any combination of these three factors. That is, a range for a suitable combination of the pressure and the treating time can be determined in correspondence to a specific preferable heating temperature. Further, when a preferable degree of pressure reduction is determined after the preferable heating temperature has been selected, a preferable range of the treating time is determined correspondingly.

These facts are related to a fact that in the heating and atmospheric or reduced pressure treatment, there happens a very small change in the surface structure of the size-controlled TiCl .O.33AlCl together with a very small reduction in the weight, and a large reduction in the weight or a change in the composition is not preferable. A very small change in crystal surface structure of size-controlled TiCl .0.33AlCl effective for the polymerization of propylene or propylene and other a-olefin is assumed to be its cause. Therefore, a combination of said three factors is a very important factor for controlling a delicate or very small change in the crystal structure. It is necessary and indispensable to exactly determine their ranges and control them to suitable ones.

The slight reduction in the weight, of the sizecontrolled TiCl .0.33AlCl at the time of heating under the atmospheric or reduced pressure is in the range of 0.1 to 0.01 by weight of the amount of sizecontrolled TiCl .0.33AlCl used i.e. in as small an amount measurable by a heat balance. The vapor pressures of individual components to be separated by vaporization or sublimation are in the order of TiCl, (which is a portion of TiCl, not removed by the abovementioned distillation and whose content prior to heat treatment is 0.01 0.l AlCl and TiCl but the actual partial pressure of TiCl is extremely small.

Also, in the treatment at a temperature of 250C or lower and for a period of time of 300 minutes or shorter, it does not occur that Al alone is much sublimated.

Thus, the portion lost during the time of heat treatment, also is considered to be TiCl .0.33AlCl In reality, the size-controlled TiCl .0.33AlCl after heat treatment, has no change in the composition, within the range of analytical errors. This is the same with the content of TiCl, as impurity.

As a result of extensive studies, we have succeeded in exactly determining a range of a suitable combination of the above-mentioned three factors. That is, when the heating time is expressed by T (C), the atmospheric pressure or the degree of pressure reduction by p (mm Hg), and the treating time by Q (minute), a range for T, P and O, which satisfies the following formulae, is a condition for treating the TiCl .O.33AlCl to be used in the present invention:

Treating condition (I) 4. l O E 300 5.0.01 2 P 760 The treating condition, which satisfies the following conditions, is more preferable.

Treating condition (ll) 6. 9.09 X l0' T 2.39 X P 3.80 X 10Ql Tr. 3.78 X l0 T 2.70 X 10P 3.79 X l0' Ql B. l T 220 l0. 0.1 P E 760 The accompanying drawing illustrates a three dimensional scope which satisfies the above-mentioned treating condition I. In this drawing, the co-ordinate axes T,

P and Q represent temperature ("C), pressure (mm Hg) and time (min.) in the heat treatment of the catalyst,

respectively. A cube is formed based on the equations (3), (4) and (5) whose corner points are i.j,k,l, etc.

The plane formed by uniting four points a, b, c and d is the one given by the formula l excluding the case where the sign is inequal, that is,

9.52 X [0"T 6.26 X lO' P 3.98 X lO' Q =1 (1') Similarly, the plane formed by uniting four points e, f, g and I1 is the one given by the formula (2) excluding the case where the sign of the formula is inequal, that is.

For example, the temperature of the point lying on the first plane also on an edge line a, e, is sought by following procedures: By inserting into P and Q in the above-mentioned formula l values of 760 and 1, respectively, a value of T z 1 10 is obtained.

The scope defined by the treating condition I l) (5)) corresponds to a space enclosed by the abovementioned two planes (a,b,c,d) and (e,f,g,h) and six planes (a,d,i,h,e), (a,e,f,l,b), (f,l,k,j,g), (c,d,i,j,k), (b,l,k,c) and (g,j,i,h).

The co-ordinate values of the above-mentioned As the organoaluminum compound having the general formula, AlR X or AlRX (this AlRX is used only in a combination with Si(OEt) differently from AlR X), which is used in a combination with said sizecontrolled TiCl .O.33AlCl heat-treated under the atmospheric or reduced pressure, the compounds whose R or R is such hydrocarbon residue as alkyl, aryl, aralkyl, alkaryl, cycloalkyl, etc., are used, but particularly the compounds whose R or R is such a lower alkyl group as ethyl, propyl, butyl, etc., are preferable. X represents a halogen atom. Among these compounds, for example, diethylaluminum chloride, ethylaluminum dichloride combined with Si(OEt).,, diisopropylaluminum chloride, diisobutylaluminum chloride, etc. are preferable. It is substantially possible to use them in a mixture with triethylaluminum.

It is also possible in the polymerization of the present invention to carry out a gaseous phase polymerization by contacting propylene or propylene and other a-olefin in a gaseous phase with the catalyst without using any solvent. Furthermore, it is possible to carry out polymerization in a liquid olefin without using any solvent, but the polymerization is usually carried out in an inert solvent. As the inert solvent, non-polymerizable hydrocarbons and chlorinated hydrocarbons are particularly preferable. For example, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, etc.; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, etc.; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, etc.; chlorinated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, a-chloronaphthalene, etc.; hydrocarbon mixtures such as kerosene, light oil, etc. are preferable. It is preferable to use every solvent after purification, for example, dehydration, deoxidation, desulfurization, etc.

The polymerization condition is not particularly limited, and the well-known condition is applicable. Preferable polymerization condition is a temperature between room temperature and C and a pressure between atmospheric pressure and l00 kglcm' G.

To control a molecular weight of a crystalline polymer formed according to the present invention to a proper value, the polymerization can be carried out in the presence of hydrogen. A small amount of hydrogen has an action to increase a rate of polymerization.

Electron donors such as amines, polyethers, organophosphorus compounds, etc., for exmple, triethylamine, pyridine, diethyleneglycol dimethylether, tris- (N,N-dimethyl) phosphoramide, etc. may be added, as the third component, to a combination catalyst of the size-controlled TiCl .O.33AlCl heat-treated under the atmospheric or a reduced pressure and the organoaluminum compound of the present invention, but there is no need of addition of a third component in case of a combination of AlRX and Si(OEt) The polymerization can be carried out in the presence of a catalyst containing the above-mentioned third component.

As the a-olefin used in the combination with propylene, which is applicable to the present invention, for example, ethylene, butene-l, pentene-l, 4-methylpentene-l, etc. can be used alone or in combination.

The present invention will be explained in detail hereunder, referring to preparation of the sizecontrolled TiCl .0.33AlC1 and reference or comparative examples and examples of the present invention, but the present invention is not limited to the following examples so long as the present invention is not beyond the spirit and scope of the present invention.

Preparation 1 (Size-controlled TiCl .0.33AlCl A material consisting of TiCl and AlCl was prepared by the reaction of TiCl, and Al powders in a mol ratio of TiCl, to Al of greater than 3:1, an excessive amount of TiCl was separated by distillation and the resulting product was dried to give 6 kg of massive solid product, which was charged in a revolving ball mill consisting of an air tight cylindrical vessel having a diameter of 80 cm and a length of 50 cm and containing steel balls of each 44.5 mm diameter whose volume in bulk is 17 l and treated with 30 R.P.M. for 10 hours to give size-controlled TiCl .0.33AlC1 whose particle size distribution was 45 particles of 325 mesh pass, 27 of those in the range of 200 300 mesh pass and 28 of those of 200 mesh on.

Preparation 2 (Size-controlled TiCl .0.33AlC1 800 g of the same solid product as that of Preparation 1 was charged into a vibrating mill composed of an air tight, mild steel vessel of a diameter of 16 cm and a length of 16 cm and containing 50 balls of each 36.5 mm diameter and the mill was operated for 20 hours with a circular vibration of 5 mm amplitude and 1000 v.p.m. to give a size-controlled TiCl .0.33A1Cl The size distribution of the product was as follows:

46 7?. 325 mesh pass '71. 200 385 mesh 29 7 200 mesh on REFERENCE EXAMPLE 1 Into a stainless steel, electromagnetic stirring type autoclave having a capacity of 1.5 l flashed with nitrogen gas under vacuum were added 1.0 l of purified hexane, 0.5 g of diethylaluminum chloride, 0.3 g of a sizecontrolled TiCl .0.33AlCl catalyst (prepared in Preparation l) and 40 ml of H (in the terms of the normal temperature and the normal pressure) in this order, and then the autoclave was heated with stirring.

After the temperature was elevated to C, polymerization was carried out for one hour while supplying propylene at 10 kg/cm G so that the pressure might become constant. After completion of the polymerization, ml of methanol was added to the content, and the mixture was treated at 70C for 30 minutes. After completion of the treatment, the resulting polymer slurry was filtered, and the polymer cake was dried under vacuum, whereby 101 g of white solid polymers were obtained. On the other hand, the filtrate was evaporated to dryness, whereby 5.4 g of amorphous polymers were found to be contained therein. The ratio of hexane-solubles to total polymers produced was 100 X 5.4/(5.4 101) 5.1 The thus obtained white solid polymer had a melt index of 7.0 according to the ASTM procedure. The melt index will be hereinafter abbreviated to M1.

REFERENCE EXAMPLE 2 In the same autoclave as in Reference Example 1 were added 1.0 l of purified hexane, 0.5 g o. diethylaluminum chloride, 0.34 g of a size-controlled TiCl .0.- 33AlC1 (prepared in preparation 1) and ml of H (in terms of the normal temperature and the normal pressure), in this order, and then the autoclave was heated with stirring. After the temperature was elevated to 63C, propylene was fed to the autoclave at 8 kg/cm G so that the pressure might become constant. After 20 minutes, 1.4 g of ethylene was added thereto over a period of 5 seconds. After 30 minutes from the start of blowing ethylene, 1.4 g of ethylene was again added thereto over a period of 5 seconds. Such operation was repeated total four times (5.6 g of ethylene). During that operation, propylene partial pressure was kept at 8 kg/cm G by supplying propylene thereto. After completion of the polymerization, 100 ml of methanol was added to the content, and the resultant mixture was treated at 63C for 30 minutes. After completion of the treatment, the resulting polymer slurry was filtered, and the polymer cake was dried under vacuum, whereby 177 g of white solid polymers were obtained. On the other hand, the filtrate was evaporated to dryness, whereby 27.6 g of amorphous polymers were found to be contained therein. The ratio of the hexane-solubles to the total polymers formed was 13.5

The ethylene content of the thus obtained white solid polymers was found 2.60 by weight by infra-red spectral analysis. M1 was 8.0.

REFERENCE EXAMPLE 3 Into the same autoclave as in Reference Example 1 were added 1.0 l of purified hexane, 0.5 g of diethylaluminum chloride, 0.25 g of a size-controlled TiCl .0.- 33AlCl (prepared in Preparation 1) and 40 ml of H (in terms of the normal temperature and the normal pressure) in this order, and then the autoclave was heated with stirring. After the temperature was elevated to 70C, polymerization was carried out for 2 hours, while supplying propylene thereto at 10 kg/cm G so that the pressure might become constant. Then, the autoclave was cooled to 60C, and unreacted propylene was purged until the pressure was lowered to 2 leg/cm G. Then, 50 ml of H (in terms of the normal temperature and the normal pressure) was added thereto, and a gas mixture of ethylene-propylene was added thereto so that the ethylene concentration of a gas phase of the autoclave might be 20 by volume and the pressure might be kept at 3 kg/cm G. The po-- lymerization was carried out for 100 minutes. Then, I ml of methanol was added to the content, and the resultant mixture was treated at 60C for 30 minutes.

After completion of the treatment, the resulting polymer slurry was filtered, and the resulting polymer cake was dried under vacuum, whereby 17.5 g of white solid polymers were obtained.

EXAMPLES 1 l6 Into a flat bottom, glass flask having a capacity of 100 ml flashed with a nitrogen gas under vacuum was filled 30 g of a size-controlled TiCl .0.33AlCl (prepared in Preparation 1) and heat treatment was carried out at a predetermined temperature and pressure for a predetermined time with stirring under the following conditions. 0.3 g each of the heat-treated TiCl .0.33AlCl was used and homopolymerization of propylene was carried out in the same procedure as in Reference Example l. The results are shown in Table I.

Table 1 Conditions for treat- Amount ing TiCI '0.33AlCl of white Hex- Condi- Condisolid ane- Run Temp. Time Prestion tion polymer solu- Ml Note No. sure I II formed bles Ref. l -C min. -mmHg l0l g 5.1% 7.0 Example 1 2 70 30 760 x x 105 4.8 6.5 Example l 3 H0 30 760 0 x 102 3.9 6.8 2 4 I40 760 0 0 I00 3.0 7.3 3 5 I90 30 760 O 0 I05 23 7.2 4 6 I40 30 2-3 0 0 I07 2.8 6.7 5 7 I90 180 2-3 0 0 I05 21 6.9 6 8 300 240 23 x x 30.0 5.0 7.0 7 9 I00 60 760 x x 98 4.7 8.0 8 I0 120 I 2-3 0 0 I00 3.5 6.5 9 l I I20 120 760 0 x I04 4.l 7.3 l0 I2 I80 IO 0 0 103 2.0 7.2 ll 13 I80 240 760 0 0 I08 2.5 8.3 l2 I4 230 30 100 0 x 98 3.7 7.4 l3 I5 230 120 760 x x 92 4.5 6.9 l4 I6 200 I20 760 0 x l0l 3.6 7.5 l5 I7 200 120 2-3 0 0 103 2.5 8.0 16

Note X: The condition does not fall within the scope of the treating conditions. 0: The condition falls within the scope of the treating conditions.

Condition I: The treating conditions (I) I (5)) as defined beforev Condition II: The treating conditions (II) ((6) (10)) as defined before.

EXAMPLES l7 21 By using the TiCl .0.33AlCl obtained by heat treatment under the atmospheric or reduced pressure according to the methods of Run Nos. 1 l7, copolymerization of propylene-ethylene was carried out in the same procedure as in Reference Example 2. The results are shown in Table 2.

Table 2 Conditions for treating Amount TiCl '0.33AlCl of white Hex- Ethysolid anelene Run Temp. Time Prespolymer solu- Ml con- Note No. sure formed bles tent Ref. 18 I77 g l3.5% 8.0 2.60% Example 2 min 09mmHg l9 C 30 760 179 13.0 8.3 2.65 Example 17 20 I40 30 2-3 183 9.9 7.8 2.65 18 2I I90 15 760 I 8.5 7.5 2.70 19 22 I 180 2-3 183 8.0 7.7 2.75 20 23 I80 30 I0 I89 7.4 7.6 2.60 2l Note Run No. 19: TiCl:,'0.33AlCl,, treated in the same manner as in No. 2.

Run No.

TiCl -,'0.33AlCl, treated in the $211119 manner III NO. 6.

Run No. 21:

are satisfied.

Run No. 22:

TiCl;,'0.33AlCl treated in the same manner as in No. 7.

Run No.

TiCl -0.33AlCl treated in the same manner as in No. 12.

EXAMPLES 22 24 By using a TiCl .0.33AlCl obtained by heat treatment under a reduced pressure according to the methods of Run Nos. 1 l7, block copolymerization of procompletion of the polymerization, unreacted propylene was purged, and 500 ml of methanol was added to the content. The resultant mixture was treated at 80C for 30 minutes. As a result, 206 g of white solid polymers pyleneethylene w c r i d t i th Same manner as was obtained. This white solid polymer was extracted in Reference Example 3. The results are shown in by boiling hexane to give a ratio of hexane-solubles to Table 3. total polymers produced, of 3.2 MI was 8.3.

Table 3 Conditions for treating Amount TiCl -O.33AlCl of white Hex- Ethy solid anelene Run polymer solu- Ml con- Note No. Temp. Time Pressure formed blcs tent Ref. 24 175 g 3.0 7.0% Example 3 min. mmHg 140C 2-3 I80 13 2.5 7.5 Example 22 26 190 120 2-3 l77 ll 2.3 7.6 23 27 I80 30 l0 185 10.5 2.2 7.5 24

Note Run No. 25: TiCl -0.33AlCl treated in the same manner as in No. 6. Run No. 26: Both treating conditions I and ll are satisfied. Run No. 27: TiCl '0.33AlCl treated in the same manner as in No. 12.

REFERENCE EXAMPLE 4 EXAMPLE 26 Reference Example 1 was followed except that puri- Reference Example 5 was followed except that fied monochlorobenzene was used in place of purified TiCl .0.33AlCl treated in the same manner as in Exhexane, and 105 g of white solid polymers was ob- 30 ample 7 was used, and 211 g of white solid polymers tained. The ratio of monochlorobenzene-solubles to was obtained. The ratio of hexane-solubles to total total polymers produced was 5.5 MI was 5.4. polymers produced was 1.1 Ml was 8.4.

EXAMPLE 25 REFERENCE EXAMPLE 6 Reference Example 4 was followed except that the Reference Example was fifllowefd except that g of EADC (ethylaluminum dichloride) and 0.2 g of S1 T1Cl .0.33AlCl treated in the same manner as in Ex- (OEt) (tetraethoxysilane) were used in place of 0.5 g ample 7 was used, and 108 g of white solid polymers of diethylalummum chlorlde of Reference Example I. was obtained. The ratio of monochlorobenzene- 84 g of white solid polymers was obtained. The ratio of solubles to total polymers produced was 3.9 MI was 5 9 4O hexane-solubles to total polymers produced was 5.5 7v.

' MI was 7.4.

REFERENCE EXAMPLE 5 EXAMPLE 27 Into the same autoclave as in Reference Example 1, Reference Example 6 was followed except that were added 600 g ofliquefied propylene, 0.5 g of dieth- 45 TiCl .0.33AlCl treated in the same manner as in Exylaluminum chloride, 0.2 g of size-controlled TiCl -,.O.- ample 7 was used, and 83 g of white solid polymers was 33AlCl (prepared in Preparation 1) and 1.5 lof H (in obtained. The ratio of hexane-solubles to total polyterms of the normal temperature and the normal presmers produced was 3.5 M] was 7.0. sure), in this order. Temperature was elevated to C, The results of Reference Examples 4 to 6 and Examand polymerization was carried out for one hour. After 50 ples 25 to 27 are shown in Table 4.

Table 4 Treating Conditions Treating Amount of of TiCl;,().33AlCl;, Condition Production Condi Condiof White Run Pres tion tion Solid Hexanc Ml Note No. Temp. Time sure I ll Polymer soluble C min. mmHg g Ref. 28 5.5 5.4 EX. 4 29 190 2-3 0 0 108 3.0 5.9 Ex. 25

Ref. 30 206 3.2 8.3 Ex. 5 31 180 2-3 0 0 211 1.1 7.4 Ex. 20

Ref. 32 84 5.5 75 Ex. 6 33 190 1110 2-3 0 0 83 3.5 7.0 Ex. 27

Note

Run Nos. 2*), 3|. 33:

Catalyst treatment was same with that of laample (1.

What is claimed is:

l. A process for producing crystalline propylene polymers which comprises contacting propylene or a mixture of propylene and another a-olefin, with a catalyst comprising l. a size-controlled and heat-treated TiCl .0.33AlCl and 2. a dialkylaluminum monohalide having the general formula of AIR- X (wherein R is a hydrocarbon rad- :ical and X is a halogen atom) or a combination of an alkylaluminum dihalide having a general formula of AlR'X (wherein R' is a hydrocarbon radical and X is a halogen atom) and Si(OC l-l 3. said size-controlled and heat-treated TiCl .0.-

.33AlCl being prepared by reacting TiCl with Al powders in a mol ratio of TiCl to A] greater than 3:1, removing unreacted TiCl size-controlling the resulting powders of TiCl .0.33AlCl by ballmilling in a revolving or vibrating ball-mill contain ing the same or substantially the same size of steel or stainless steel balls having a diameter of 25 50 mm, at room temperature, to give size-controlled powders consisting of 50% or more of the particles of 325 meshes on and less than 50% of the particles of 325 meshes pass, and heat-treating the sizecontrolled powders:

a. at a temperature (T) which satisfies the conditions 100C T 250C.,

b. at a pressure (P) which satisfies the conditions 0.01 mmHg P 5 760 mmHg,

n. for a time (O) which satisfies the condition 1 min- Mile .2 0 300 minutes,

and wherein the following relationship between T, P and Q is maintained:

3. A process according to claim 1, wherein the organo-aluminum compund is diethylaluminum chloride, ethylaluminum dichloride plus Si(OC l-l ethylaluminum sesquichloride, diisopropylaluminum chloride or diisobutylaluminum chloride.

4. A process according to claim 1 wherein the contacting is carried out at room temperature to 160C under atmospheric pressure to kg/cm G.

5. A process according to claim 1 wherein said another a-olefin is ethylene, butene-l, pentene-l, or

4-methylpentene-l alone or in combination. 

1. A PROCESS FOR PRODUCING CRYSTALLINE PROPYLENE POLYMERS WHICH COMPRISES CONTACTING PROPYLENE OR A MIXTURE OF PROPYLENE AND ANOTHER A-OLEFIN, WITH A CATALYST COMPRISING
 1. A SIZE-CONTROLLED AND HEAT-TREATED TIC13, 0.33 ALCL3 AND
 2. A DIALKYLALUMINUM MONOHALIDE HAVING THE GENERAL FORMULA OF ALR2X (WHEREIN R IS A HYDROCARBON RADICAL AND X IS A HALOGEN ATOM) OR A COMBINATION OF AN ALKYLALUMINUM DIHALIDE HAVING A GENERAL FORMULA OF ALR''X2 (WHEREIN R'' IS A HYDROCARBON RADICAL AND X IS A HALOGEN ATOM) AND SI(OC2H5)4,
 2. The method according to claim 1 wherein the titanium component is subjected to a heat treatment: a. at a temperature (T) which satisfies the conditions 120*C < or = T < or = 220*C., b. at a pressure (P) which satisfies the conditions 0.1 < or = P < or = 760 mmHg, c. for a time (Q) which satisfies the condition 3 minutes < or = Q < or = 300 minutes, AND wherein the following relationship between T, P and Q is maintained d. 9.09 X 10 3T - 2.39 X 10 4 P + 3.80 X 10 4 Q > or = 1 e. 3.78 X 10 3T + 2.70 X 10 4 P + 3.79 X 10 4 Q > or =
 2. a dialkylaluminum monohalide having the general formula of AlR2X (wherein R is a hydrocarbon radical and X is a halogen atom) or a combination of an alkylaluminum dihalide having a general formula of AlR''X2 (wherein R'' is a hydrocarbon radical and X is a halogen atom) and Si(OC2H5)4,
 3. said size-controlled and heat-treated TiCl3.0.33AlCl3 being prepared by reacting TiCl4 with Al powders in a mol ratio of TiCl4 to Al greater than 3:1, removing unreacted TiCl4, size-controlling the resulting powders of TiCl3.0.33AlCl3 by ball-milling in a revolving or vibrating ball-mill containing the same or substantially the same size of steel or stainless steel balls having a diameter of 25 - 50 mm, at room temperature, to give size-controlled powders consisting of 50% or more of the particles of 325 meshes on and less than 50% of the particles of 325 meshes pass, and heat-treating the size-controlled powders: a. at a temperature (T) which satisfies the conditions 100*C < or = T < or = 250*C., b. at a pressure (P) which satisfies the conditions 0.01 mmHg < or = P < or = 760 mmHg, c. for a time (Q) which satisfies the condition 1 minute < or = Q < or = 300 minutes, and wherein the following relationship between T, P and Q is maintained: d. 9.52 X 10 3T - 6.26 X 10 5P + 3.98 X 10 4Q < or = 1 and e. 3.53 X 10 3T + 2.94 X 10 4P + 3.54 X 10 4Q < or =
 1. 3. A process according to claim 1, wherein the organo-aluminum compund is diethylaluminum chloride, ethylaluminum dichloride plus Si(OC2H5)4, ethylaluminum sesquichloride, diisopropylaluminum chloride or diisobutylaluminum chloride.
 3. SAID SIZE-CONTROLLED AND HEAT-TREATED TIC13.0.33ALCL3 BEING PREPARED BY REACHING TICL WITH AL1 POWDERS IN A MOL RATIO OF TICL4 TO A1 GREATER THAN 3:1, REMOVING UNREACTED TICL4, SIZE-CONTROLLING THE RESULTING POWDERS OF TICL3.0.33ALC13 BY BALL-MILLING IN A RELVOLVING OR VIBRATING BALL-MULL CONTAINING THE SAME OR SUBSTANTIALLY THE SAME SIZE OF STEEL OR STAINLESS STEEL BALLS HAVING A DIAMERER OF 25 - 50 MM, AT ROOM TEMPERATURE, TO GIVE SIZE-CONTROLLED POWDERS CONSISTING OF 50% OR MORE OF THE PARTICLES OF 325 MESHES ON AND LESS THAN 50% OF THE PARTICLES OF 325 MESHERS PASS, AND HEAT-TREATING THE SIZE-CONTROLLED POWDERS: A. AT A TEMPERATURE (T) WHICH ATISFIES THE CONDITIONS 100*C $ T $ 250*C., B. AT A PRESSURE (P) WHICH SATISFIES THE CONDITIONS 0.01 MMHG $ P $ 760 MMHG, C. FOR A TIME (Q) WHICH SATISFIES THE CONDITION 1 MINUTE $ Q $ 300 MINUTES, AND WHEREIN THE FOLLOWING RELATIONSHIP BETWEEN T, P AND Q IS MAINTAINED: D. 9.52X10**-3T-6.26X10**-5P+3.98X10**-4Q $ AND E. 3.53X10**3T+2.94X10**-4P+3.54X10**-4Q $
 1. 4. A process according to claim 1 wherein the contacting is carried out at room temperature to 160*C under atmospheric pressure to 100 kg/cm2G.
 5. A process according to claim 1 wherein said another Alpha -olefin is ethylene, butene-1, pentene-1, or 4-methylpentene-1 alone or in combination. 